import type { DirectiveBinding } from 'vue'
import { isObject } from 'lodash-es'
import './style.less'

// v-ripple
// v-ripple.center
// v-ripple="{ class: 'text-red-500' }"

export interface RippleOptions {
  /** 自定义`ripple`颜色，支持`unocss` */
  class?: string
  /** 是否从中心扩散 */
  center?: boolean
  circle?: boolean
}

export interface RippleDirectiveBinding
  extends Omit<DirectiveBinding, 'modifiers' | 'value'> {
  value?: boolean | { class: string }
  modifiers: {
    center?: boolean
    circle?: boolean
  }
}

function transform(el: HTMLElement, value: string) {
  el.style.transform = value
  el.style.webkitTransform = value
}

function calculate(e: PointerEvent, el: any, value: RippleOptions = {}) {
  const offset = el.getBoundingClientRect()

  // 获取点击位置距离 el 的垂直和水平距离
  const localX = e.clientX - offset.left
  const localY = e.clientY - offset.top

  let radius = 0
  let scale = 0.3
  // 计算点击位置到 el 顶点最远距离，即为圆的最大半径（勾股定理）
  if (el._ripple?.circle) {
    scale = 0.15
    radius = el.clientWidth / 2
    radius = value.center
      ? radius
      : radius + Math.sqrt((localX - radius) ** 2 + (localY - radius) ** 2) / 4
  }
  else {
    radius = Math.sqrt(el.clientWidth ** 2 + el.clientHeight ** 2) / 2
  }

  // 中心点坐标
  const centerX = `${(el.clientWidth - radius * 2) / 2}px`
  const centerY = `${(el.clientHeight - radius * 2) / 2}px`

  // 点击位置坐标
  const x = value.center ? centerX : `${localX - radius}px`
  const y = value.center ? centerY : `${localY - radius}px`

  return { radius, scale, x, y, centerX, centerY }
}

const ripples = {
  show(e: PointerEvent, el: any, value: RippleOptions = {}) {
    if (!el?._ripple?.enabled) {
      return
    }

    // 创建 ripple 元素和 ripple 父元素
    const container = document.createElement('span')
    const animation = document.createElement('span')

    container.appendChild(animation)
    container.className = 'v-ripple__container'

    if (value.class) {
      container.className += ` ${value.class}`
    }

    const { radius, scale, x, y, centerX, centerY } = calculate(e, el, value)

    // ripple 圆大小
    const size = `${radius * 2}px`

    animation.className = 'v-ripple__animation'
    animation.style.width = size
    animation.style.height = size

    el.appendChild(container)

    // 获取目标元素样式表
    const computed = window.getComputedStyle(el)
    // 防止 position 被覆盖导致 ripple 位置有问题
    if (computed && computed.position === 'static') {
      el.style.position = 'relative'
      el.dataset.previousPosition = 'static'
    }

    animation.classList.add('v-ripple__animation--enter')
    animation.classList.add('v-ripple__animation--visible')
    transform(
      animation,
      `translate(${x}, ${y}) scale3d(${scale},${scale},${scale})`,
    )
    animation.dataset.activated = String(performance.now())

    setTimeout(() => {
      animation.classList.remove('v-ripple__animation--enter')
      animation.classList.add('v-ripple__animation--in')
      transform(animation, `translate(${centerX}, ${centerY}) scale3d(1,1,1)`)
    }, 0)
  },

  hide(el: any | null) {
    if (!el?._ripple?.enabled)
      return

    const ripples = el.getElementsByClassName('v-ripple__animation')

    if (ripples.length === 0)
      return
    const animation = ripples[ripples.length - 1] as HTMLElement

    if (animation.dataset.isHiding)
      return
    else animation.dataset.isHiding = 'true'

    const diff = performance.now() - Number(animation.dataset.activated)
    const delay = Math.max(250 - diff, 0)

    setTimeout(() => {
      animation.classList.remove('v-ripple__animation--in')
      animation.classList.add('v-ripple__animation--out')

      setTimeout(() => {
        const ripples = el.getElementsByClassName('v-ripple__animation')
        if (ripples.length === 1 && el.dataset.previousPosition) {
          el.style.position = el.dataset.previousPosition
          delete el.dataset.previousPosition
        }

        if (animation.parentNode?.parentNode === el)
          el.removeChild(animation.parentNode)
      }, 300)
    }, delay)
  },
}

function isRippleEnabled(value: any): value is true {
  return typeof value === 'undefined' || !!value
}

function rippleShow(e: PointerEvent) {
  const value: RippleOptions = {}
  const element = e.currentTarget as any | undefined

  if (!element?._ripple || element._ripple.touched)
    return

  value.center = element._ripple.centered
  if (element._ripple.class) {
    value.class = element._ripple.class
  }

  ripples.show(e, element, value)
}

function rippleHide(e: Event) {
  const element = e.currentTarget as any | null
  if (!element?._ripple)
    return

  window.setTimeout(() => {
    if (element._ripple) {
      element._ripple.touched = false
    }
  })
  ripples.hide(element)
}

function updateRipple(
  el: any,
  binding: RippleDirectiveBinding,
  wasEnabled: boolean,
) {
  const { value, modifiers } = binding
  const enabled = isRippleEnabled(value)
  if (!enabled) {
    ripples.hide(el)
  }

  el._ripple = el._ripple ?? {}
  el._ripple.enabled = enabled
  el._ripple.centered = modifiers.center
  el._ripple.circle = modifiers.circle
  if (isObject(value) && value.class) {
    el._ripple.class = value.class
  }

  if (enabled && !wasEnabled) {
    el.addEventListener('pointerdown', rippleShow)
    el.addEventListener('pointerup', rippleHide)
  }
  else if (!enabled && wasEnabled) {
    removeListeners(el)
  }
}

function removeListeners(el: HTMLElement) {
  el.removeEventListener('pointerdown', rippleShow)
  el.removeEventListener('pointerup', rippleHide)
}

function mounted(el: HTMLElement, binding: RippleDirectiveBinding) {
  updateRipple(el, binding, false)
}

function unmounted(el: any) {
  delete el._ripple
  removeListeners(el)
}

function updated(el: HTMLElement, binding: RippleDirectiveBinding) {
  if (binding.value === binding.oldValue) {
    return
  }

  const wasEnabled = isRippleEnabled(binding.oldValue)
  updateRipple(el, binding, wasEnabled)
}

export const vRipple = {
  name: 'ripple',
  mounted,
  unmounted,
  updated,
}
